The present technology relates to a display unit capable of performing two-dimensional display (planar display) and three-dimensional display (stereoscopic display), and to an illumination device suitably applicable to a backlight of such a display unit.
Display units capable of performing three-dimensional display include display units in which it is necessary for a viewer to wear special glasses and display units in which it is unnecessary for a viewer to wear special glasses. The latter display unit uses a lenticular lens or a parallax barrier in order to allow a stereoscopic picture to be visually observed with naked eyes. Picture information is divided into information for a right eye and information for a left eye by the lenticular lens or the parallax barrier, and thus different pictures are observed by the right and left eyes. As a result, three-dimensional display becomes possible.
In the case where the above-described parallax barrier is used, however, resolution in two-dimensional display is degraded. Therefore, a technology of performing three-dimensional display without impairing the resolution in two-dimensional display is disclosed in PTL 1. In PTL 1, a parallax barrier is configured of a liquid crystal element, and the liquid crystal element becomes a parallax barrier in three-dimensional display by making a non-transmissive region. Then, in two-dimensional display, making the entire surface be transmissive prevents the liquid crystal element from becoming a parallax barrier, and thus the entire picture on a display screen equally enters right and left eyes of a viewer.